you can test the trigger to the coil really easy with a test light.
assuming your one coil has 2 wires,(not counting the secondary wire that goes to the cap) one should have battery voltage when key on and the other should have a pulsing ground from the ignition module or distributor. with the test light connected to a good ground(verify by touching the positive battery cable) probe one wire to make sure it has battery voltage. If it does then your other wire will be for the trigger.
now attach your test light to the positive terminal on the battery( verify connection by now touching a good ground)
probe the other wire while cranking the engine. If the test light flickers then the coil should be firing.
Now since you have replaced the coil and assuming it is not defected out of the box, and the light is flickering, then you need to check your secondary wire to the cap, as well as the cap and rotor, maybe it got wet?
If it is not flicking then your need to check your pick up coil or ignition module, which I would need to see a pic or know what kind of distributor it is.
I was an auto mechanic but I am new to the boat world. but should be the same concept.